Liquid fuel pumps



2, 1966 K. A. w. KEMP 3,263,614

LIQUID FUEL PUMPS Filed Dec. 5, 1963 5 Sheets-Sheet 1 1966 K. A. w. KEMP 3,253,514

LIQUID FUEL PUMPS Filed Dec. 5, 1963 5 Sheets-Sheet 2 K. A. W. KEMP 5 Sheets-Sheet 4 Filed Dec. 5, 1965 z- 1966 K. A. w. KEMP 3,263,614

LIQUID FUEL PUMPS Filed Dec. 5, 1963 5 Sheets-Sheet 5 15 V )2 n 11 (O8 United States Patent 3,263,614 LIQUID FUEL PUMPS Kenneth Albert Walters Kemp, Ealing, London, England, assignor to C.A.V. Limited, London, England Filed Dec. 5, 1963, Ser. No. 328,359 6 Claims. (Cl. 103-2) This invention relates to liquid fuel pumps for internal combustion engines, the pump being of the kind comprising in combination a body part, a rotary distributor in the body part, a head formed or secured at one end of the distributor, said head having formed therein a transverse bore, at least one plunger in the bore, an annular cam surrounding the head and whereby inward movements will be imparted to the plunger as the head rotates, a longitudinal passage formed in the distributor in communication with said bore, an outlet passage in communication with the longitudinal passage, a plurality of angularly spaced outlet ports in the body part with which the outlet passage is adapted to register in turn as the distributor rotates, and feed means for feeding fuel under pressure to the longitudinal passage whilst the outlet passage is out of register with the outlet ports.

The object of the invention is to provide in a pump of this kind convenient means for varying the maximum quantity of fuel which can be fed to the engine.

According to the invention a pump of the kind specified comprises in combination a cylinder in the body part, an axially movable shuttle or the equivalent in the cylinder, an adjustable stop for limiting movement of the shuttle or its equivalent in one direction, and co-operative ways in the distributor and body part respectively whereby whilst said outlet passage is in register with any one of said outlet ports, one end of the cylinder is placed in communication with the feed means whilst the other end of the cylinder is open to a spill passage, and whereby, whilst the outlet passage is out of register with the outlet ports said one end of the cylinder is opened to the longitudinal passage and the other end of the cylinder is in communication with said feed means.

In the accompanying drawings:

FIGURE 1 is a sectional side view of an example of the invention showing the pump during the injection stroke, the section being taken on the line 11 of FIG- URE 3.

FIGURE 2 is a sectional side view of the pump in the same position but with the section taken on the line 2-2 of FIGURE 3 wherein the plane of the section is 45 removed from the plane of the section of FIGURE 1.

FIGURE 3 is a section on the line 3-3 of FIGURE 1.

FIGURE 4 is a section on the line 44 of FIGURE 1.

FIGURE 5 is a section on the line 55 of FIGURE 1.

FIGURE 6 is a section on the line 6-6 of FIGURE 1.

FIGURE 7 is a sectional side view similar to FIGURE 1 except that the rotary parts have moved through 45".

FIGURE 8 is a sectional side view similar to FIGURE 2 but with rotary parts as shown in FIGURE 7.

FIGURE 9 is a section on the line 99 of FIGURE 7.

FIGURE 10 is a section on the line 10-10 of FIG- URE 7.

FIGURE 11 is a section on the line 11-11 of FIG URE 7.

FIGURE 12 is a section on the line 12-12 of FIG- URE 7.

FIGURE 13 is a view similar to FIGURE 7 showing a modification of the invention, and

FIGURE 14 is a section on the line 1414 of FIG- URE 13.

Referring first to the example of the invention illustrated in FIGURES 1 to 12 the pump is intended for supplying fuel to a four cylinder engine. The composite pump comprises a body part 100 which at one end ice contains a feed pump 101. The feed pump 101 has an inlet and an outlet formed in the body part, the inlet and outlet being interconnected by a spring loaded relief valve not shown which limits the pressure which can be generated by the pump to a predetermined value, pressures below this predetermined value varying with speed.

At the other end of the body part is contained an injection pump which includes a rotary head 102 having formed in it a transverse bore 103. The bore extends diametrically through the head and contains a pair of reciprocable plungers 104. As the head rotates each plunger is moved inwardly at an appropriate timing by the interaction of a roller 105 at its outer end with a surrounding annular cam 106.

The rotary parts of the feed and injection pumps are interconnected by a cylindrical distributor 107, and are adapted to be driven as a unit by the engine with which the pump is associated. In the distributor 107 is formed an axial passage 108 which at one end is in communication with the bore 103 in the head, and which at its opposite end is in communication with a substantially radial outlet passage 109 formed in the distributor. The outlet passage 109 communicates, as the distributor rotates, with each in turn of four equi-angularly spaced outlet ports 110 in the body part, the outlet ports 110 being adapted for connection to four injection nozzles associated with the four cylinders of the engine respectively.

In the body part is an annular chamber 111 to which fuel is supplied from the feed pump 101 through a feed passage 112. Fuel can flow from this chamber through a throttle valve 113, which is adjustable manually or by a governor, to a first passage 114 in the body part which is in communication with a circumferentially extending groove 115 in the distributor. In communication with the groove 115 there are formed in the periphery of the distributor four equi-angularly spaced and longitudinally extending grooves 116. The grooves 116 are arranged to register in turn, as the distributor rotates, with a port 117 in the body part in communication with the inner end of a cylinder 118 formed in the body part and extending substantially radially relative to the distributor. In the outer end of the cylinder 118 is a screw stop 119 which can be adjusted from the exterior of the body part to determine the degree'of outward movement permitted to a shuttle 120 contained within the cylinder. The outer end of the cylinder is also in communication through a second passage 121 in the body part with a second circumferentially extending groove 122 formed in the periphery of the distributor. Extending from the groove 122 is a single longitudinally extending groove 123 in the periphery of the distributor this groove 123 being arranged to register, as the distributor rotates with each in turn of a first series of four equi-angularly spaced passages 124 which are in communication with the space surrounding the head 102, this space in turn being in communication with the fuel reservoir. The groove 123 is also arranged to communicate in turn, as the distributor rotates, with a second series of four equi-angularly spaced passages 125 in the body part communicating with the annular chamber 111; the first and second series of passages 124, 125 in the body part being displaced from one another by 45.

There is also formed in the distributor a third series of four equi-angularly spaced passages 126 which at their inner ends are in communication with the axial passage 108. The third series of passages 126 are angularly displaced from the grooves 116 by 45, and are adapted to register in turn, as the distributor rotates, with the port 117 in the body part communicating with the inner end of the cylinder 118.

In-operation, as the plungers 104 are moved inwardly by their interaction with the annular cam 106, fuel is displaced from the axial passage in the distributor through the outlet passage 109 to the appropriate outlet port 110. At the same time fuel is fed by the feed pump 101 to the inner end of the cylinder 118 by way of the annular chamber 1111, the throttle valve 113, the first passage 114, the circumferential groove 115, and one of the longitudinally extending grooves 116. As a result the shuttle 120 is moved outwardly towards the stop 119 thereby displacing fuel from the outer end of the cylinder by way of the second passage 121 in the body part, the circumferential groove 122, the single longitudinal groove 123, and one of the first series of passages 124 to the reservoir. It will be understood that when the throttle valve 113 is partially closed the shuttle will not move into contact with the stop.

At a position 45 subsequently, fuel is fed to the outer end of the cylinder by way of the annular chamber 111, one of the second series of passages 125, the single longitudinally extending groove 123 in the distributor, the circumferential groove 122 and the second passage 121 in the body part. As a result the shuttle 120 is moved inwardly thereby displacing fuel from the inner end of the cylinder 118 by way of one of the third series of passages 126 to the axial passage 108 in the distributor, thus moving the plungers 104 apart ready for the next injection stroke.

It will be appreciated from the foregoing that the permitted stroke of the shuttle 120 will determine the maximum quantity of fuel which can be fed to the engine, and that this maximum quantity can be varied by adjustment of the stop 119 from the exterior of the body part. It is also to be understood that by increasing or reducing the number of passages 124, 125 and 126 in the first, second and third series respectively, the number of longitudinally extending grooves 116, and the number of outlet ports 110 so as to correspond to the number of cylinders in the engine, a pump suitable for use with more or less than four cylinders can readily be designed.

In order to permit a quantity of fuel in excess of the maximum for which the stop 119 has been set, when starting, the first passage 114 may be in communication with a by-pass passage 127 incorporating a manually operable valve 128. The end of the passage 127 at the downstream side of the valve is disposed to register in turn with the passages 126 of the third series as the distributor rotates, and at the instants when the passages 126 are in register with the port 117. When the valve 128 is open, additional fuel can be fed through it to the axial passage 108 thereby ensuring that the plungers 104 are moved outward to the limit of their travel even though the stop 119 has been set to provide a maximum fuel setting below the maximum capacity of the pump.

In the modification of the invention illustrated in FIG- URES 13 and 14 a shuttle 129 is provided intermediate the end of the axial passage 108 in the distributor, and two further radially disposed passages 130 and 131 are formed in the distributor, the inner ends of these passages being in communication with the axial passage 108. The passage 130 is adapted to register, as the distributor rotates, with each in turn of the second series of passages 125 in the body part at an instant subsequent to the instant at which communication is established between the inner end of the cylinder 1.18 and each of the third series of passages 126 in the distributor. The plungers 104 are thus moved outward to the limit of their travel irrespective of the travel of shuttle 129. Thus the plungers 104 always start to move inwardly by their interaction with the cam 106 at a fixed predetermined instant in the cycle. The other radial passage 131 is in communication with the circumferential groove 122 in the distributor, and is arranged to be uncovered by the shuttle 129 as the latter is moved forwardly as a result of the inward movements of the plungers 104 to cause fuel from the opposite side of the shuttle to be discharged to an engine cylinder. When the radial passage 131 is uncovered surplus fuel can spill by way of the circumferential groove 122, and the single longitudinal groove 123 to the appropriate passage of the first series of passages 124 in the body part, and thereby terminate injection. Thus by this modification injection commences at a predetermined instant in the cycle irrespective of the quantity of fuel which has been fed to the distributor under the control of the throttle valve 113 and the shuttle 120.

The shuttle in the cylinder 118 may take various forms such, for example, as a purely cylindrical shuttle, as shown, or a cylindrical shuttle having a conical end arranged to seat within the port 117, or alternatively it may take the form of a ball having a complementary seating at the entrance to the port 117.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. A liquid fuel pump for supplying fuel to an internal combustion engine, comprising in combination a body part, a rotary distributor mounted in the body part, and arranged to be driven into timed relationship with the engine with which the pump is associated, a head supported on the distributor for rotation therewith, a bore formed in said head and accommodating a plunger, a cam mounted in the body part in a position adjacent the head, so that when the head rotates inward movement will be imparted to the plunger, a longitudinal passage formed in the distributor, said passage being in communication at one end with said bore, an outlet passage formed in the distributor, said outlet passage being in communication at one end with the longitudinal passage, a plurality of angularly spaced outlet ports formed in the body part and with which the other end of the outlet passage communicates in turn as the distributor rotates, so that as the plunger is moved inwardly by the cam fuel will be displaced to one of the outlet ports, a cylinder formed in the body part, a shuttle movable in said cylinder, a stop for limiting the movement of the shuttle in one direction, a fuel supply passage in the body part to which fuel is fed under pressure, a spill passage in the body part, a plurality of inlet passages formed in the distributor in communication with the longitudinal passage therein, an inlet port in the body and with which said inlet passages register in turn as the distributor rotates during at least part of the time the delivery passage is out of register with the delivery port, said inlet port communicating with one end of said cylinder, a groove on the periphery of the distributor, said groove communicating with the other end of said cylinder and being arranged to register in turn with the spill passage and the fuel supply passage, the registration of said groove with the supply passage taking place whilst said inlet port is in communication with an inlet passage, a plurality of angularly spaced grooves formed on the periphery of the distributor and disposed to register in turn as the distributor rotates with said inlet port and during the time when said inlet port is out of register with the inlet passages, said plurality of grooves communicating with the feed means, and a throttle valve for controlling the rate at which fuel can flow to said inlet port, the arrangement being that as fuel is fed to said inlet port the shuttle will be moved towards said stop, fuel being allowed to escape from the other end of the cylinder by way of said groove and said spill passage, and when said groove registers with said supply passage fuel will flow to the other end of the cylinder thereby moving the shuttle in a direction away from the stop and causing the fuel contained in said one end of the cylinder to be delivered to said bore.

2. A liquid fuel pump as claimed in claim 1 in which said stop is adjustable from the exterior of the pump thereby to enable the maximum quantity of fuel which can be delivered by the pump to be varied.

3. A liquid fuel pump as claimed in claim 2 comprising a second shuttle slidably mounted in the longitudinal passage in the distributor between said inlet passages and said bore, said second shuttle being movable towards said head by the fuel fed to the longitudinal passage through an inlet passage, and movable in the opposite direction to discharge fuel to an inlet port during the inward movement of the plunger.

4. A liquid fuel pump as claimed in claim 3 comprising a further spill passage arranged to be uncovered by said second shuttle when the latter has moved away from the head a predetermined extent, a further inlet passage in the distributor in communication with the longitudinal passage intermediate the bore and the second shuttle, and a further inlet port in the body part and with which the further inlet passage can register to enable the bore to be completely filled with fuel after the movement of the second shuttle towards the head has terminated.

5. A liquid fuel pump as claimed in claim 2 including 15 a bypass passage in the body and disposed so as to communicate in turn with said inlet passages during the outward movement of the plunger, valve means being provided to enable said bypass passage to be opened to allow 6. A liquid fuel pump as claimed in claim 4 including a bypass passage in the body and disposed so as to communicate in turn with said inlet passages during the outward movement of the plunger, valve means being provided to enable said bypass passage to be opened to allow an excess quantity of fuel to be delivered by the pump.

References Cited by the Examiner UNITED STATES PATENTS 3,025,797 3/1962 Hutcheon 1032.1 3,035,523 5/1962 Kemp et al 103-2.1 3,058,425 10/1962 Evans 103-2.1 3,107,661 10/1963 Kemp 103-2.1

MARK NEWMAN, Primary Examiner.

DONLEY J. STOCKING, Examiner.

an excess quantity of fuel to be delivered by the pump. 20 W. J. KRAUSS, Assistant Examiner. 

1. A LIQUID FUEL PUMP FOR SUPPLYING FUEL TO AN INTERNAL COMBUSTION ENGINE, COMPRISING IN COMBINATION A BODY PART, A ROTARY DISTRIBUTOR MOUNTED IN THE BODY PART, AND ARRANGED TO BE DRIVEN INTO TIMED RELATIONSHIP WITH THE ENGINE WITH WHICH THE PUMP IS ASSOCIATED, A HEAD SUPPORTED ON THE DISTRIBUTOR FOR ROTATION THEREWITH, A BORE FORMED IN SAID HEAD AND ACCOMMODATING A PLUNGER, A CAM MOUNTED IN THE BODY PART IN A POSITION ADJACENT THE HEAD, SO THAT WHEN THE HEAD ROTATES INWARD MOVEMENT WILL BE IMPARTED TO THE PLUNGER, A LONGITUDINAL PASSAGE FORMED IN THE DISTRIBUTOR, SAID PASSAGE BEING IN COMMUNICATION AT ONE END WITH SAID BORE, AN OUTLET PASSAGE FORMED IN THE DISTRIBUTOR, SAID OUTLET PASSAGE BEING IN COMMUNICATION AT ONE END WITH THE LONGITUDINAL PASSAGE, A PLURALITY OF ANGULARLY SPACED OUTLET PORTS FORMED IN THE BODY PART AND WITH WHICH THE OTHER END OF THE OUTLET PASSAGE COMMUNICATES IN TURN AS THE DISTRIBUTOR ROTATES, SO THAT AS THE PLUNGER IS MOVED INWARDLY BY THE CAM FUEL WILL BE DISPLACED TO ONE OF THE OUTLET PORTS, A CYLINDER FORMED IN THE BODY PART, A SHUTTLE MOVABLE IN SAID CYLINDER, A STOP FOR LIMITING THE MOVEMENT OF THE SHUTTLE IN ONE DIRECTION, A FUEL SUPPLY PASSAGE IN THE BODY PART TO WHICH FUEL IS FED UNDER PRESSURE, A SPILL PASSAGE IN THE BODY PART, A PLURALITY OF INLET PASSAGES FORMED IN THE DISTRIBUTOR IN COMMUNICATION WITH THE LONGITUDINAL PASSAGE THEREIN, AN INLET PORT IN THE BODY AND WITH WHICH SAID INLET PASSAGES REGISTER IN TURN AS THE DELIVERY PASSAGE IS OUT OF AT LEAST PART OF THE TIME THE DELIVERY PASSAGE IS OUT OF REGISTER WITH THE DELIVERY PORT, SAID INLET PORT COMMUNICATING WITH ONE END OF SAID CYLINDER, A GROOVE ON THE PERIPHERY OF THE DISTRIBUTOR, SAID GROOVE COMMUNICATING WITH THE OTHER END OF SAID CYLINDER AND BEING ARRANGED TO REGISTERIN TURN WITH THE SPILL PASSAGE AND THE FUEL SUPPLY PASSAGE, THE REGISTRATION OF SAID GROOVE WITH THE SUPPLY PASSAGE TAKING PLACE WHILST SAID INLET PORT IS IN COMMUNICATION WITH AN INLET PASSAGE, A PLURALITY OF ANGULARLY SPACED GROOVES FORMED ON THE PERIPHERY OF THE DISTRIBUTOR AND DISPOSED TO REGISTER IN TURN AS THE DISTRIBUTOR ROTATES WITH SAID INLET PORT AND DURING THE TIME WHEN SAID INLET PORT IS OUT OF REGISTER WITH THE INLET PASSAGES, SAID PLURLAITY OF GROOVES COMMUNICATING WITH THE FEED MEANS, AND A THROTTLE VALVE FOR CONTROLLING THE RATE AT WHICH FUEL CAN FLOW FED TO SAID INLET PORT THE ARRANGEMENT BEING THAT AS FUEL IS FED TO SAID INLET PORT THE SHUTTLE WILL BE MOVED TOWARDS SAID STOP, FUEL BEING ALLOWED TO ESCAPE FROM THE OTHER END OF THE CYLINDER BY WAY OF SAID GROOVE AND SAID SPILL PASSAGE, AND WHEN SAID GROOVE REGISTERS WITH SAID SUPPLY PASSAGE FUEL WILL FLOW TO THE OTHER END OF THE CYLINDER THEREBY MOVING THE SHUTTLE IN A DIRECTION AWAY FROM THE STOP AND CAUSING THE FUEL CONTAINED IN SAID ONE END OF THE CYLINDER TO BE DELIVERED TO SAID BORE. 